Circuit interrupter



Feb. 9,1943. E. H. HALL. mL 2,310,779

CIRCUIT INTERRUPTER Feb. 9,1943.

E. H. HALL ET AL CIRCUIT INTERRUPTER 3 Sheets-Sheet 2 Filed Oct. 24 1941 WITNESsEs: my /.KMMM

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Feb. 9, 1943.

E. H. HALL ET AL. 2,310,779

CIRCUIT INTERRUPTER Filed oct. 24, 1941 'i 5 sheets-sheet 5 Patented Feb. 9, 1943 UNiTED STATES PATENT OFFICE CIRCUIT INTERRUPTER Vania Application October 24, 1941, Serial No. 416,360

15 Claims. (Cl. 2GB- 148) This invention relates to improvements in circuit interrupters, and, more particularly, to operating mechanisms for actuating the gas blast valve of circuit interrupters of the gas blast type.

In the patent application of R. C. Cunningham and B. P. Baker, Serial No. 357,696, filed September 2l, i940, and assigned to the assignee of the instant application there is shown and described a gas blast valve operating mechanism which functions to open the blast valve during the opening operation of the breaker, and which keeps the blast valve closed during the closing operation of the breaker to conserve the supply of compressed gas. In the valve operating mechanism of the aforesaid application there is provided means to open the gas blast Valve when the breaker is closed on an overloaded circuit.

In the aforesaid application the operating mechanism consisted of a rotatable roller assembly which was operated during the opening operation oi the breaker by a cam attached to the main operating shaft of the breaker. During the closing operation of the breaker the roller assembly was rotated to an inoperative position. When the breaker in the aforesaid application was closed during the existence of overload conditions in the circuit connected to the breaker, or when there was a reversal of the contact mechanism before the contacts were fully closed, a pin was provided on the cam to rotate the roller assembly to an operative position. However, the rotation of the ro-ller assembly by the pin when the breaker was closed on an overloaded circuit required a certain amount of time, and there was consequently a delay before the gas blast valve was operated to extinguish the arc drawn.

The present invention, although operating in a generally similar manner, is an improvement in the gas blast valve operating mechanism decribed in the aforesaid application. It is an improvement in at least three respects. In the present invention, by the utilization of a plurality of compression springs instead of one compression spring which was used in the aforesaid application, there results a greater flexibility in the gas blast valve operating mechanism. The design of suitable compression springs is consequently greatly facilitated.

Also in the present invention there is provided a greater flexibility of adjustment of the rotatable roller assembly. whereas in the aforesaid application adjustment in only one direction was permitted. One of the most important improvements of the present invention over the mechanism described in the aforesaid application is the fact that in the present invention when the breaker is attempted to be closed during the existence of overload conditions in the external circuit connected to the interrupter the gas blast valve is immediately (without any delay) operated to extinguish the arc drawn during such an opening operation.

The main object of the present invention is to provide a gas blast valve operating mechanism which is reliable under all operating conditions and which conserves arc extinguishing gas during the closing of the breaker.

Another object of the present invention is to provide a gas blast valve operating mechanism which will open the blast valve immediately upon a reversal of the Contact operating mechanism when the breaker is closed on an overloaded circuit.

It is another object of the present invention to provide an improved gas blast valve operating mechanism which has a great flexibility of adjustment, and the parts of which may easily be designed for long life and reliable operation.

Other objects and advantages will become apparent from the following description when taken in connection with the accompanying drawings, in which:

Figure l is a side elevational view, partly in section, of a gas blast type of circuit interrupter illustrating our invention and shown in the closed circuit position;

Fig. 2 is an enlarged side elevational view of the blast valve operating mechanism of the interrupter shown in Fig. 1, and showing the disposition of the parts during a normal opening operation of the interrupter;

Fig. 3 is a view similar to Fig. 2, but illustrating the positions of the several parts during a closing operation of the interrupter;

Fig. 4 is an enlarged fragmentary front elevational view of the interrupter shown in Fig. 1 to indicate the need for flexibility of adjustment, some of theyparts being shown in cross-section; and,

Fig. 5 is an enlarged side elevational fragmentary View, partly in section, of a modified gas blast valve operating mechanism, and showing the disposition of the parts thereof during an opening operation from an intermediate closing position.

Referring to the drawings, and in particular to Fig. l, the reference numeral I designates a storage tank for storing gas, such as air, under pressure. Extending from the upper end of the storage tank l is a relatively short .flanged conduit 3 which, in turn, carries a valve casing 5. Secured to the upper end of the valve casing is a tubular insulator 1 which has secured to its upper end an insulating support 9. The insulating support 9 may be given additional support by an insulating member I I. The support 9 carries a stationary contact assembly I3 which, in this instance, is enclosed within an arc extinguishing structure I5, only a portion of which is shown. The arc extinguishing structure I5 may be of conventional form and does not concern the present invention.

Coacting with the stationary contact assembly I3 is a movable contact I1 which is preferably of blade-like construction and generally shaped, and mounted for swinging movement about a pivot I9 carried by a conducting bracket 2 I. External circuit connections to the interrupter are made through a pair of terminal members 23 and 25, the iirst of which is secured to the stationary contact assembly I3, and the second one of which is connected to the conducting bracket 2 I Thus, when the interrupter is in the closed circuit position as shown in Fig. l, an electrical circuit is established between the terminals 23 and 25 through thestationary contact I3, the movable contact I1 and the conducting bracket 2L The movable contact I1 is actuated to open and closed circuit positions by an insulating operating rod 21 actuated by the crank arm 29 carried by a shaft 3i, in turn journaled in a suitable bracket 3,3. The shaft SI is actuated by a crank arm coupled by suitable linkage 31 to the connecting rod 35 of an air actuated piston operated within the cylinder 4 I. The connecting rod 3 8 may be moved up and down to effect respective closing and opening movements of the movable contact I1 by the admission of compressed gas from the storage tank I to the operating cylinder tII by suitable valves well known in the art. l

The tubular insulator 1, in addition to serving as a support, also provides a passage for conducting an arc extinguishing blast of gas from the storage tank I to the space between the contacts I3VV and I1. This gas blast passage proceeds through the short conduit 3, through valve casing 5, through the tubular insulator 1, and opening 43 provided through the insulating support 9 which is preferably coextensive with the passage within the tubular insulator 1.

In the event the moving contact I1 is moved to the open circuit position while the circuit interrupter is carrying load, an arc will be drawn across the upper end of passage 43 and will be subjected to a blast of arc extinguishing gas caused to flow through the tubular insulator 1, whereby the arc will be extinguished. Control of the blast of gas to the arc in this instance may be obtained by a valve 4.5 disposed in the lower end of the valve casing 5. The valve 45 has a stem 41 operatively coupled to one end of an actuating member fig. In this instance the actuating member I3 is rigidly secured to a rock shaft 5I journaled in the side of the valve casing 5. The shaft 5I extends exteriorly of the casing 5, and has a pair of rocker arms 53 secured to the opposite ends thereof. The rocker arms 53 carry a rotatable roller, assembly generally indicated at 55 in Fig. l, which is adapted to be actuated by a cam 51 in this instance forming an integral part of the crank arm 29.

A more complete illustration of the arrangement of the roller assembly 55 in connection with the other operative parts of the gas blast valve operating mechanism will be found in Figs. 2te 4, inclusive.

The two rocker arms 53 are joined by a pin 5S. A spring guide rod EI is pivotally mounted on the pin 53 and has its upper end slidably operative in a bracket 53 which is an integral extension of the valve casing 5. A compression spring S5 encircling the spring guide rod 6I biases the rocker arms 53 in a counter-clockwise direction about the rock shaft 5I.

Two pivot screws 61, as clearly shown in Fig. 4, threadably secured to the rocker arms 53 pivo-tally support a lever latch, generally indicated by the reference numeral 69. rhe lever latch 55 comprises two metallic plates 1I, the upper ends of which are pivotally mounted on the pivot screw 51 and the lower ends of which are joined together by a pin 13. A spring guide rod 15 is pivotally supported on the pin 59 and has its lower end slidably operative in a hole 16 drilled through the pin 13. A compression spring 11 encircling the spring guide rod 15 biases the lever latch 69 in a clockwise direction about the pivot screws @1 looking at Figs. 2v, 3 or 5.

Each plate 1I has a projection 13 which is biased against the pin 59 by compression spring 11 and serves as a stop for the clockwise rotation of the lever latch 59 about pivot screws 61. Also each metallic plate 'II has a slot 3i formed therein, the purpose for which will appear hereinafter. Pivotally mounted on the pivot screws E1 and disposed between the two metallic plates 1I is a U-shaped yoke member 83. In the bight of the U-shaped yoke member 83 is drilled a hole 85, through which is adjustably inserted the stem 83 of a U-shaped roller yoke 81. The U-shaped roller yoke 81 is adjustably secured to the U-shaped yoke member 83 by two nuts 9 I and 93, nut 5I having an upper extension 92 which projects through the hole 85 and is threadably engaged by the nut 33 as most clearly shown in Fig. 3. A pin 55 passes through the parallel legs of the U-shaped yoke member S3 and pivotally supports a spring guide rod S1, the other end of which is slidably operative in an eyelet |53 which is rotatably supported on a bracket IGI, the bracket IGI being an integral extension of the rocker arm 53. A compression spring 89 encircling the spring guide rod S1 biases the U-shaped yoke member 83 in a clockwise direction about the pivot screws 61 in Figs. l, 2, 3 `and 5.

A pin |55 carrying a roller I1 passes through holes provided in the parallel legs of the U- shaped roller yoke 81. It also passes very loosely through the parallel legs of the U-shaped yoke member 83 as shown at Q in Fig. 4 and through the slots BI in the two plates 1 I. The ends of the pin are surrounded by sleeves 96 which normally rest against adjustable stop screws I D9 which are threadably secured to the ends of the rocker arms 53. A pin II I rigidly secured to the cam 51 and disposed perpendicularly with respect to the plane thereof is provided for a purpose which will appear hereinafter.

The operation of the gas blast valve operating mechanism will now be explained. When the crcuit interruptor, which is shown in the closed circuit position in Fig. 1, is actuated to the open circuit position, the crank arm 29 is rotated in a counter-clockwise direction about the shaft 3I. The movable contact I1, which is attached through the insulating operating rod 21 to the crank arm 29, is rotated in a counter-clockwise direction about its pivot IS to result in opening the electrical circuitthrough the breaker and in drawing an arc between the movable contact I1 and the. stationary contact I3. At the same time that` the crank arm 29 is rotating in a counterclockwise direction about the shaft 3|, the leading edge of the cam 51, which is an integral part of the crank arm 29, engages the roller I01 and forces the rocker arms 53 in a clockwise direction about the rock shaft 5I against the bias of compression spring 65. Depending on the shape of the cam surface, the blast valve is correspondingly held open during the opening operation of the circuit interrupter.

It is thus apparent that during the opening operation of the circuit interruptor when an arc is being drawn between the movable contact I1 and the stationary contact I3, an arc extinguishing blast of gas from the storage tank I is admitted through the tubular insulator 1 to result in an extinguishment of the arc. The disposition of the parts during a normal opening operation is shown by the full lines in Fig. 2.

When. the electrical circuit is desired to be completed through the interrupter, the crank arm 29 is rotated by the shaft 3l in a clockwise direction. The cam 51 also rotates in a clockwise direction about the shaft 3l. During the closing operation of the interrupter the lower leading cam edge I I3 strikes against the roller I01, and the entire roller assembly, consisting of the U-shaped roller yoke 81 and the U-shaped yoke member 83, is rotated in a counter-clockwise direction about the pivot screws 61 to result in the roller I01 being forced to an inoperative position and sliding over the top surface of the cam 51 in a manner as shown by the full lines in Fig. 3. It is thus apparent that during the closing of the circuit interrupter the roller I01 is pushed to an inoperative position and consequently the valve 45 remains closed during the entire closing operation of the interruptor. This conserves the gas stored in the storage tank I and renders theperformance of the interruptor more economical. During the closing operation the pin I I I strikes the plates 1I forcing them slightly in a counterclockwise direction about the pivot screws 61 against the bias of compression springs 11 until the pin III snaps past the plates 1I, the latter then returning to their original position.

Occasionally it may occur that the external circuit conditions are such that an overload condition exists during the time when it is desired to close the breaker. Consequently the trip mechanism may be operated before the contacts I1 and I3 fully engage. The trip mechanism (not shown) may bev actuated therefore before the breaker is fully closed and before the roller I01 has returned to its operative position. It is desirable to provide means during the closing operation for instantaneously opening the blast valve 45 upon a reversal of the contact operating mechanism even though the roller I01 is not in an operative position.

Y The pin I I I, which is in a position adjacent to the surfaces II5 of the plates 1I at this time, engages the faces Il5 of the metallic plates 1I and serves to open the gas blast valve 45 immediately upon a reversal of the contact operating mechanism during a closing operation before the contacts of the breaker are fully closed. It is apparent-that the force exerted by the pin III on the faces I I5 of the metallic plates 1I is in a direction to the left ofthe pivot screws 51 as shown by the dotted lines in Fig. 3, and consequently the lever latch 69 will be raised and will result in a clockwise movement of the rocker arms 53 about the rocker shaftV 5I to effect an opening of the blast valve 45. The pin III will remain in engagement with the surfaces II5 of plates 1I to hold the blast valve 45 open the desired length of time during such an abnormal opening operation. The dotted lines in Fig. 2 show the moment of separation of the pin I I I from the surface II5 of the plates 1 I, at which time the valve 45 will again close.

It is thus apparent that We have provided a gas blast valve operating mechanism which functions to open the blast valve during the opening operation of the breaker, the blast valve remaining closedv during the closing operation of the breaker. We have also provided means for instantaneously opening the gas blast valve upon a reversal of the contact operating mechanism during the closing operation caused by the actuation of the trip mechanism before the contacts are fully closed.

It will be readily apparent that by the provision of three compression springs 65, 11, and 99 we have eliminated thediculty of overworking a single compression spring. It will furthermore be apparent that the position of the pin III immediately adjacent to the lower surfaces II5 of the plates 1I is such that there will occur an immediate (not a delayed) opening of the valve 45 upon a reversal of the contact operating mechanism during the closing operation caused by an actuation of the trip mechanism before the contacts I3 and I1 are fully closed. Thus the reversal of the contact operating mechanism during a closing operation, which draws an are between the contacts I3 and I1, will actuate the pin I I I against the faces I I5 of the metallic plates 1I and force the lever latch 69 upwards to result in an immediate opening of the blast valve 45 to extinguish the arc drawn between the contacts I3 and I1.

For each pole of the interrupter there is provided an identical gas blast valve operating mechanism. It is desirable to have flexibility in the adjustment of the rollers I01 so that all of the blast valves 45 of the several poles of the interrupter will be opened at the same time and will remain open for the same length of time. For this purpose we have provided an adjustment of the roller I01 in two perpendicular directions. The adjustable roller stop screws |09 provided at the end of each rocker arm 53 provide an adjustment in one direction, and the two nuts 9I and 93 provide an adjustment of the roller stem 89 in a direction at right angles thereto. We have consequently provided great flexibility in the adjustment of the position of the roller I01. It is possible to adjust the roller I01 associated with the gas blast valve operating mechanism associated with each pole of the breaker so that the valves 45 of all of the poles may be operated simultaneously and for the same length of time. It may be desired, however, to have the valve 45 of one pole of the breaker operate prior to the operation of one or more of the other valves 45 associated with the other poles of the breaker, and in this event the adjustment is also easily made.

Fig. 4, showing a fragmentary front elevational view of the interrupter shown in Fig. 1, clearly indicates the ease of adjustment of the position of the several rollers I01 to have simultaneous operation of all the blast valves 45 of the breaker. Only two poles are shown, but it is obvious that there may be more.

The embodiment of our invention shown in Fig. 5 is the same as that shown in the other figures,

the. previousiigures f so'v as to; easily: snap .'sequen tiall'yfpastthe! notches ILI 1; during' a; closing: opere.

ationl of. the breaker as Vpreviously f described: B y'` the I provision of afmultiplicit'yv of: notches IiITf on the plates II We have provided for a greater numberf of." immediate; opening. positions.. of; the

valve '45..Whe'n the. Contact ol'aeraizilng.''rnecllansmV isvr reversed duringfa. closing 'operation prior to;

full-fclosureo the contacts.l I3: and. II. During. normal closing "of the; breaker, thepin, I;-I;Ii will simply snapipas't'each'notch VII`1 However; if

at anyintermediate. position;4 of thex pin. IiI.I:` thev contact operating mechanism is reversed yduring a closing .operation as a. result of. the, actuation of the Vtriplmechanism prior. to'. full-.closure ofthe contacts I3 and II, then the pinr III: will'. catch on the .notch I ITI .Where it is then'positoned'; the

levier latchi SSJWill beiraised;'andthezvalve i5- willjimmediatelvbe opened. Consequently, for variousl intermediate closing positions. of r the pin I I.'I."tlf1erefWill` be. animmadiate; opening. o f. thev valve 45.!uponal reversal 'of the.` contact operating mechanismfduringla closing: operation. prio;` :to

full closure of, thecontacts I3zand Il, and prior,Y

ofcourse., tolaresctting of .the roller. yoke 85T to an operativeV position. L By; la suitable'. configuration;

oiv the notches' I I 'I i and of. theiplates' 'I I the valve. may be heldl open/for a1 desired period:of time during such anabnormal opening. operation.

From theV foregoing` it` is. apparent that We have-.provided-a novel valve operating'mecha.- nism associated with a gas blast type. of circuit breaker which provides. flexibility of adjustment, a4 multiplicity of. compression springsto` same are for the purposes oiY illustration andtha-t changes and modifications may be made therein byA those skilled in the art Without departing` from the spirit andscope of theappended claims.

We claim as oui` invention:

1. In a circuit -interrupter of -thegas-blast type, separable contacts for establishing an arc, operatingmeans for actuating saidV contacts tov open and to closed positions, a valve arrangedto be supplied with gas under pressure, an actuating member for operating said valve to establish anarc extinguishing blast of gas, said contact operating means including a member movable in accordance with the openingand closing movements ofsaid contacts, said member having acam surface, an additional actuating portion carried by said member, a coacting camI roller hingedly secured vte said valve-actuating member, means biasing saidy cam rollerA to` an operative position With respect to said` valve actuating member to cause said cam surface to engagefsaidcam roller and Vthus tooperatesaid valveA actuating member duringthe'riermal opening -movement of said contacts, said-cam roller being movableto an inoperativeu position relative' to said valve actuating memberA without imparting motionk te said valve actuating member-during the closing movement of said contacts, and-'means comprisingY a rotatable member'- pivotally supg ported b'ysaid valve-actuatingmemberandrotataai-.awed

bui-.the platesfIIlof the lever. latch 69.; arenotchedf alongonesideas shownby' the reference numeral;` IIJ. f The pin. I.'IlI maybe madeA smaller than. in

ablelwithl respect thereto. to engagel said: addi-` tional?actuating portion soasV to operate said.

valve .actuating member to -open` saidy valvel in. the event of reversal of-'saidcontactv operating means prior'to. closureorf-I said contacts'- during a clos ing opera'tiori` of said interrupter and` While said.

cam roller is Vin inoperativerpositioni.

2. y In a circuitinterrupterI of` the gas-blast type,

plied-Withgas under pressure, anactuating membei'.V for operatinglsaid valve Sto. establish an4 arc extinguishing. blast oil'gas," said'A contactoperating.

meansQincludin'gfa member movable inlaccord'- ance withltheopeningandrclosing movements of.y said contacts, said memberl having aLcam'surface;

an oft-standingmember rigidly. secured 'toi said member, a'l 'coa'cting-V camro1lerl pivotally securedH to said valve actuating member, 'means biasing-` said camroller to an operativeposition with'respect tosaid.` valve actuating-r member tocause'- said cam rsurface toengage saidcam roller to operate said: valve'actuating member during the normal opening. movement ofA said contacts, said. caml roller` being movable ltoaninoperative posiL-.

tion* during:y theY closing movementcrsaid contacts, and means comprising ainember rotatable withgrespect to saidfvalve actuating. member, said.v

last mentionedmember cooperating with said oistanding member toactuate said valve actuating member toppen said valve in the eventY of. re-

versalof contact movement during a closing op.

erationof theinterrupter prior to Afullclosure of saidJ contactsand also during the time when.

saidcamroller in is aninoperative position.

3. In a circuit interrupter of the gas-blasttype,A separableI contactsv for. establishingV an arc, oper.-l

atingmeans for actuating said contactsto open and-to closedpositions, a valve-arranged to be supplied with gasY under pressure, an actuating memberVV for operating said'valveto establishan, arc extinguishing.blastY of. gas, said contact .oper. ating meansA including amember movable in ac-..

cordancewith` the.A openingV and closing movements-cf' saidV contacts, said member having. a.

cam surface, a transverse pin rigidly securedto said member, a coacting cam roller. hingedly. se-

cured to said valve actuating member, means,

biasing said cam roller toanoperative position withv respect4 to saidvalve actuating memberv to cause said cam surface to operate said valve ac.- tuating member during the normal opening movement of said contacts, saidcam roller being. movable to an inoperativeposition during the closing operation of Ysaid interrupter, and .means comprisinga memberpivotally supported by said valve actuating member and.operative by said pinto open-saidvalveduring a.reversal of contact movement during aclosing. operation of the. interrupter prior to full closure of saidcontacts and atatime Whensaid .cam roller is in an inoperative-position.

4. In a.,circuit interrupter of thegas-.blast typa: separable contacts for establishing. an arc0p, eratingmeansfor actuating said contactsto open and closed positions, a valveA arranged to be sup.- plied with gas under pressure, an actuating member for operating vsaid valve to establish an arc extinguishing blast of gas,.said contacty operating means including.. a member rotatable. in accordance-with contact movement, said rotatable :memberlhavingv a camsurface, a coactingfcamgroller hingedly secured to said valve` actuatingmember and biased to an operative positionwithrespect thereto, said cam surface engaging said cam roller duringthe normal opening operation of said interrupter to cause said valve actuating member to open said valve, said cam roller being forced by said cam to an inoperative position during at least a part of the closing operation of said interrupter, an olf-standing pin secured to said cam, and means comprising a member pivotally supported by said valve actuating member and having notches cut therein to cooperate with said off-standing pin to cause said valve to be opened substantially instantaneously upon a reversal of contact movement during a closing operation of said interrupter and prior to full closure of said contacts at a time when said cam roller is in an inoperative position.

5. In a circuit interrupter of the gas-blast type, separable contacts for establishing an arc, operating means for actuating said contacts to open and closed positions, a valve arranged to be supplied with gas under pressure, an actuating member for operating said valve to establish an arc extinguishing blast of gas, said contact operating means including a cam rotatable in accordance with contact movement, a coacting cam roller pivotally secured to said valve actuating member and biased to an operative position with respect thereto, said cam engaging said cam roller during the normal opening operation of said interrupter to cause said valve actuating member to open said valve, said cam roller being moved by said cam to an inoperative position during part o-f the closing movement of said contacts, an offstanding pin secured to said cam and substantially perpendicular to the plane thereof and movable therewith, means comprising one or more plate members pivotally secured to said valve actuating member and having a plurality of notches formed along one side thereof, said notches cooperating with said pin to force an instantaneous opening ofsaid valve upon a reversal of contact movement during a closing operation of said interrupter prior to full closure of said contacts and while said cam roller is in an inoperative posil tion.

6. In a circuit interrupter of the gas-blast typey separable contacts for establishing an arc, operating means for actuating said contacts to open and closed positions, a valve arranged to be supplied with gas under pressure, an actuating member for operating said valve to establish an arc extinguishing blast of gas, said contact operating means including a cam rotatable in `accordance with contact movement, an ofi'- standing pin rigidly secured to said cam, a U- shaped roller yoke, a coacting cam roller pivotally supported by said U-shaped roller yoke, one or more pivot screws, said U-shaped roller yoke 'being pivotally supported by said one or more pivot screws to said valve` actuating member, said cam engaging said cam roller during the normal opening operation of said interrupter to cause said valve actuating member to open said valve, said cam roller being moved by said cam during the closing operation of said interrupter to an inoperative position, one or more plate members pivotally supported by said pivot screws to said valve actuating member, said one or more plate members being engaged by said off-standing pin to cause an opening of said valve upon a reversal of contact movement during a closing operation of the interrupter prior to full closure of said contacts, and during the time when said .camroller is in an inoperative position. y 7. In a circuit interrupter of the gas-blast type, separable contacts for establishing an arc, operating means for actuating said contacts to open and closed positions, a valve arranged to be supplied with gas under pressure, one or more actuating members for operating said valve to establish an arc extinguishing blast of gas, said contact operating means including a cam rotatable with the movement of said contacts, an oilstanding pin secured to said cam, a U-shaped roller yoke, a coacting cam roller pivotally supported in said U-shaped roller yoke, one or more pivot screws, said U-shaped roller yoke being pivotally supported by said one or more pivot screws to said valve actuating members, said cam engaging said cam roller during the normal Opening operation of said interrupter to cause said valve actuating member to open said valve, said cam roller being moved by said cam to an inoperative position during the closing operation of said interrupter, one or more plate members pivotally supported on said valve actuating members by said pivot screws, notches provided along one side of said plate members to cooperate with said off-standing pin to cause a substantially immediate opening of said valve upon a reversal of contact movement during a closing operation of said interrupter prior to full closure of said contacts and while said roller is in an inoperative position.

8. In a circuit interrupter of the gas-blast type, separable contacts for establishing an arc, operating means for actuating said contacts to open and closed positions, a valve arranged to be supplied with gas under pressure, two actuating members for operating said valve to establish an arc extinguishing blast of gas, said contactoperating means including a cam rotatable in accordance with contact movement, an ofi-standing pin secured to said cam, a U-shaped roller yoke with a threaded stem, a coacting cam roller pivotally supported in said U-shaped roller yoke, a U-shaped members said stem of said U-shaped roller yoke being adjustably secured by nuts on said U-shaped member, two pivot screws threadedly secured to the opposed outer faces of said two actuating valve members, said U-shaped yoke member being pivotally supported by said two pivot screws to said two valve actuating members, said cam engaging said roller during the normal opening operation of said interrupter to cause said valve actuating members to open said valve, said cam roller being moved by said cam during the closing operation of said interrupter to an inoperative position, one or more plate members pivotally supported by said pivot screws to said valve actuating members, said one or more plate members being engaged by said offstanding pin to cause an opening of said valve upon a reversal of contact movement during a closing operation of the interrupter prior to full closure of said contacts and during the time when said cam roller is in an inoperative position.

9. In a circuit interrupter of the gas-blast type, separable contacts for establishing an arc, operating means for actuating said contacts to open and closed positions, a valve arranged to be supplied with gas under pressure, two acutating members for operating said valve to establish an arc extinguishing blast of gas, said contact operating means including a cam rotatable in accordance with Contact movement, an oistanding pin secured to said cam, a U-shaped roller yoke with a threaded stem, a coacting cam roller pivotally supported in said U-shaped roller yoke, a U-shaped member, said stem of said U- shaped roller yoke being adjustably secured by nuts on said -U -shaped member, two pivot screws threadedly secured to the Opposed outer faces of said two actuating valve members, said U-shaped yoke member being ,pivotally supported by said two pivot screws to said two valve actuating ,members7 said cam engaging said roller during the normalopening operation .of said interrupter ito ,cause said lvalve actuating members to vopen said valve, said cam roller being moved by said `cam during the closing operation of said interrupter to an inoperative position, one or more .plate members pivotally supported by said pivot screws to vsaid two-valve actuating members and having a plurality of notches along one side thereof, said notches on said plate members engaging Ywith said off-standing pin to `cause an immediate opening of said valve upon a reversal of contact movement dur-ing a .closing operation of the interrupter prior to full closure of said ,contacts and during the time when said cam roller `is in an inoperative position.

10.7In a circuit interrupter of the gas-blast type, separable contacts for establishing an arc, operating means for actuating said contacts to open and closed positions, a lvalve arranged to be supplied with `gas under pressure, two actuating members for yoperating said valve to establish an arc extinguishing blast of gas, said contact operating means including a cam rotatable in accordance with .contact movement, an ostanding pin secured to said cam, a U-shaped roller yoke with a threaded stem, a coacting cam roller pivotally supported on said U-shaped rollerv yoke, -a yU-shaped member, said stem of lsaid U-shaped roller yoke being lsecured by adjustableV screws to said U-shaped member, two pivot screws threadedly secured to the opposed outer faces of said two actuating valve members, said U -shaped yoke member being pivotally supported by said two pivot screws -to said two valve actuating members, said cam engaging said roller during the normal opening operation of said interruptor to cause said valve actuating members to open said valve, said cam roller being moved by said cam during the closing operation of said interrupter to an inoperative position, one ore-more plate members pivotally supported byv said pivot screws to said two valve actuating members, said plate members being so positioned that at a predetermined time prior to full closure of said contacts said oir-standing pin is adjacent one edge of said plate members to engage said plate members upon a reversal of contact movement to force said two valve actuating members to open said valve.

11, In `acircuit interruptor of the gas-blast type, separable contacts for establishing an arc, operating means `for actuating said contacts to open and closed positions, a valve arranged to be supplied with gas under pressure, two actuating members for operating said valve to establish'an arc extinguishing blast of gas, said contact operating means including a cam rotatable in accordance with contact movement, an oistanding pin secured to and rotatable with said cam. a U-shaped roller yoke with a threaded stem, a coacting cam roller pivotally supported on said U-shaped roller-yoke, a U-shaped member, said stem of said lU-shaped roller yoke being secured by adjustable screws to said U-shaped member, two pivot screws threadedly secured to the opposed outer faces of said two actuating valve members, said U-shaped yoke member being pivotally supported by said two pivot screws .to Vsaid two valve actuating members, said cam engaging said Aroller during the normal vopening `operation of said interruptor to cause said .valve actuating members to open said valve, said .cam roller being moved by said cam during the closing operation of said interruptor to an inoperative position, one or more plate members pivotally supported by said pivot screws to said two Valve actuating members and having a Aplurality of notches along one side thereof, said plate members being so positioned that said oi-standing .pin engages sequentially said notches during the intermediate portion of the closing operation of .said interrupter so that upon a reversal `of contact movement prior to full closure of said contacts and during the time when said `roller is in an inoperative position said lpin will cooperate with the notch which it then engages to cause opening of said valve.

12.7In a circuit interrupter of the gas blast type, separable contacts for establishing an arc, operating Imeans for actuating said vcontacts to open and to closed circuit positions, a valve arranged to be supplied with gas under pressure, an actuating .member for operating said valve to establish an arc extinguishing blast of gas, said contact operating means including a member movable in accordance with the opening and closing movements of said contacts, cam means interengaging said member with said actuating member to open said Valve during a normal opening operation of said interruptor, means rendering said cam means inoperative during at least a portion of the closing operation of said interrupter, and means mounted on said actuating member for movement independently of said cam means and operative to interengage said member with said actuating member to open said valve only when there is a reversal of contact movement during a closing operation and while said cam means is rendered inoperative.

13. In a circuit interruptor of the gas blast type, separable contacts for establishing an arc, movable means for moving said contacts to open and to closed circuit positions, a valve arranged to be supplied with gas under pressure, said movable means including a rst operating part and a second operating part, a rst valve actuating member engaging said first operating part during a normal opening operation of said nterrupter to actuate said iirst valve actuating member to open said valve, means rendering said rst valve actuating member inoperative to open said valve during at least a portion of the closing operation of said interruptor, a second valve actuating member movable with respect to said first valve actuating member, said second valve actuating member engaging said second operating part to open said valve only during a circuit opening operation while said rst valve actuating member is in its inoperative position and when there is a reversal of Contact movement during a closing operation.

14. In a circuit interruptor of the gas blast type, separable contacts for establishing an arc, movable means for moving said contacts to open and to closed circuit positions, a valve arranged to be supplied with gas under pressure, said movable means including a rst operating part and a second operating part, a rst valve actuating member, means biasing said rst valve actuating member to a position where it is operative to open said valve upon movement of said rst operating part during a normal opening operation of said interruptor. means rendering said rst valve actuating member inoperative to open said valve during at least a portion of the closing operation of said interrupter, a second valve actuating member movable with respect to said iirst valve actuating member, a second biasing means biasing said second valve actuating member to an operative position, said second valve actuating member engaging said second operating part to open said valve only during a circuit opening operation While said first valve actuating member is in an inoperative position and when there is a reversal of contact movement during a closing operation.

15. In a circuit interrupter of the gas blast type, separable contacts for establishing an arc, movable means for moving said contacts to open and to closed circuit positions, a valve arranged to be supplied with gas under pressure, said movable means including a first operating part and a second operating part, a iirst valve actuating member, means for adjusting the position of said first valve actuating member in at least two directions, said rst valve actuating member engaging said iirst operating part during a normal opening operation oi said interrupter to open said valve, means rendering said iirst valve actuating member inoperative during at least a portion of the closing operation of said interrupter, a second valve actuating member movable with respect to said first valve actuating member, said second actuating member engaging said second operating part to open said valve only during a circuit opening operation while said iirst actuating member is in an inoperative position and when there is a reversal of contact movement during a closing operation.

ERIK H. HALL.

RAYMOND H. LEITZEL. 

